Wild buckwheat (Polygonum convolvulus L.) is an annual taprooted weed. It occurs in agricultural areas in all of the Canadian provinces but is reported to be more abundant in the west than in the east. It is native to Europe and was first collected in Canada in Manitoba in 1873.
Wild buckwheat overwinters as achenes. It has a climbing growth habit which allows it to compete well in stands of cereals and other tall crops. This growth habit allows for rapid spread and coverage of bare ground or open spaces. The number of achenes produced by a single plant varies with soil type and seeding date, but under noncompetitive conditions a single plant can produce up to 30,000 achenes. Seed dispersal is normally accomplished by disturbance by farm machinery and long distance dispersal may take place through contaminated crop seed.
Due to its growth habit and abundant seed production, wild buckwheat is a competitive weed that causes significant losses in grain crops. Herbicides registered for use on wild buckwheat include dicamba, bromoxynil, combinations of these chemicals with 2,4-D or MCPA and other herbicides alone, as formulated mixtures, or in various combinations.
However, the efficiency of these chemicals is sometimes limited. Furthermore, the excessive use of chemicals is of concern for the environment and human health. It would therefore be highly desirable to have an herbicidal composition which has better and more selective properties against wild buckwheat, and which reduces the input of chemicals into the environment.